Hispanic men who have sex with men (HMSM) have been highly impacted by the HIV epidemic, both nationally and in the Miami metropolitan statistical area (MSA). Despite the urgent need, few theoretically based, culturally appropriate behavioral interventions to reduce risk of sexual acquisition or transmission of HIV among HMSM have been developed and rigorously tested Our team has been engaged in community- based HIV prevention research with HMSM (R01-DA-16026; R01 MH-62700; U-R3-CCU-41644) that informed the development of the draft curricula of Proyecto SOL, whose preliminary efficacy we are proposing to test in this application. Proyecto SOL is a theoretically grounded, culturally based, group level intervention to reduce risk of HIV acquisition or transmission among HMSM with two versions: SOL-I (for HMSM whose HIV serostatus is negative or unknown), and SOL-II (for HMSM who are HIV positive). In this application, we propose to participate in an initiative to examine preliminary efficacy of promising behavioral interventions for HMSM that has both collaborative and site specific components. In the initial phase of project, we will convene 6-8 focus groups and conduct 2 to 3 "dry-runs" to finalize the two versions (including manuals) of Proyecto SOL. We will finalize the site-specific assessment; program and bench test the ACASI, train staff etc. During this phase, we will also work with the multi-site study group to develop the core set of assessment items, control intervention (TBD-CONTROL), define the recruitment procedures etc., and complete additional activities of relevance to the initiative. During Years 2 and 3, we will conduct two parallel randomized control trials (RCT) to determine preliminary efficacy, acceptability, and feasibility of each version of Proyecto SOL compared with the TBD-CONTROL. We will test whether key factors (cultural orientation, racism, perceptions of sexual control, and internalized homonegativity) directly linked to risk and protection among HMSM in our past studies moderate intervention effects. For Study 1, we will recruit 120 HMSM of negative or unknown serostatus and randomly assign them to SOL-I or TBD-CONTROL. For Study 2, we will recruit 120 HIV positive HMSM and randomly assign them to SOL-II or TBD-CONTROL. Although we propose to recruit in community and internet venues for both studies, final decisions regarding recruitment approaches will be made collaboratively. Assessments using ACASI will be done at baseline and 3 months post intervention. Acceptability and feasibility assessments will be completed after each intervention session. Throughout the project period, we will continue to collaborate with the multi-site study group by participating in scheduled conference calls, attending meetings, preparing manuscripts, presenting at local, national and international meetings and other work of relevance to the initiative. [unreadable] [unreadable] [unreadable]